From d17e375da420c0fc23927d63c9060b0bb4789c84 Mon Sep 17 00:00:00 2001
From: crowetic <jason@crowetic.com>
Date: Wed, 16 Apr 2025 21:21:25 +0000
Subject: [PATCH] added changes - detect if underlying hardware is broadcom and
 apply different fixes if so.

---
 vm-tool-setup.sh | 61 ++++++++++++++++++++++++++++--------------------
 1 file changed, 36 insertions(+), 25 deletions(-)

diff --git a/vm-tool-setup.sh b/vm-tool-setup.sh
index 0b3ef82..125b52a 100755
--- a/vm-tool-setup.sh
+++ b/vm-tool-setup.sh
@@ -5,7 +5,7 @@ set -euo pipefail
 echo "=== [1/5] Updating system and installing tools ==="
 sudo apt update
 sudo apt -y upgrade
-sudo apt install -y qemu-guest-agent util-linux haveged ethtool
+sudo apt install -y qemu-guest-agent util-linux haveged ethtool lshw dmidecode
 
 echo "=== [2/5] Enabling qemu-guest-agent ==="
 sudo systemctl enable --now qemu-guest-agent
@@ -13,7 +13,7 @@ sudo systemctl enable --now qemu-guest-agent
 echo "=== [3/5] Trimming filesystems ==="
 sudo fstrim -av || true
 
-echo "=== [4/5] Detecting VM network interfaces ==="
+echo "=== [4/5] Detecting VM NICs ==="
 NIC_LIST=()
 for nic in /sys/class/net/*; do
     nicname=$(basename "$nic")
@@ -29,33 +29,44 @@ fi
 
 echo "VM NICs detected: ${NIC_LIST[*]}"
 
-echo "=== [5/5] Creating persistent systemd service to disable offloads ==="
-SERVICE_FILE="/etc/systemd/system/disable-vm-nic-offloads.service"
+echo "=== [5/5] Creating systemd service with conditional logic ==="
+SERVICE_FILE="/etc/systemd/system/conditional-nic-offload.service"
 
-{
-    echo "[Unit]"
-    echo "Description=Disable all VM NIC offloads at boot"
-    echo "After=network.target"
-    echo ""
-    echo "[Service]"
-    echo "Type=oneshot"
-    for nic in "${NIC_LIST[@]}"; do
-        echo "ExecStart=/usr/sbin/ethtool -K $nic tx off rx off tso off gso off gro off"
-        echo "ExecStart=/sbin/ip link set $nic txqueuelen 10000"
-    done
-    echo "RemainAfterExit=yes"
-    echo ""
-    echo "[Install]"
-    echo "WantedBy=multi-user.target"
-} | sudo tee "$SERVICE_FILE" > /dev/null
+sudo tee "$SERVICE_FILE" > /dev/null <<EOF
+[Unit]
+Description=Disable NIC offloads only if KVM + Broadcom detected
+After=network-online.target
+Wants=network-online.target
 
-echo "=== Enabling and starting NIC offload disable service ==="
+[Service]
+Type=oneshot
+ExecStart=/bin/bash -c '
+HYPERVISOR=\$(systemd-detect-virt)
+BROADCOM_FOUND=\$(lspci | grep -i "broadcom" || true)
+if [[ "\$HYPERVISOR" == "kvm" && -n "\$BROADCOM_FOUND" ]]; then
+  echo "✅ Broadcom NIC on KVM detected — applying NIC tuning";
+$(for nic in "${NIC_LIST[@]}"; do
+    echo "/usr/sbin/ethtool -K $nic tx off rx off tso off gso off gro off;"
+    echo "/sbin/ip link set $nic txqueuelen 10000;"
+done)
+else
+  echo "❌ Skipping NIC tuning — not KVM with Broadcom NIC"
+fi
+'
+RemainAfterExit=yes
+
+[Install]
+WantedBy=multi-user.target
+EOF
+
+echo "=== Reloading systemd and enabling service ==="
+sudo systemctl daemon-reexec
 sudo systemctl daemon-reload
-sudo systemctl enable --now disable-vm-nic-offloads.service
+sudo systemctl enable --now conditional-nic-offload.service
 
-echo "=== ✅ VM NIC setup complete ==="
+echo "=== ✅ VM NIC conditional optimization complete ==="
 for nic in "${NIC_LIST[@]}"; do
     echo "--- $nic ---"
-    ethtool -k "$nic" | grep -E 'segmentation|offload|scatter|checksum'
-    ip link show "$nic" | grep txqueuelen
+    ethtool -k "$nic" | grep -E 'segmentation|offload|scatter|checksum' || true
+    ip link show "$nic" | grep txqueuelen || true
 done